The prior art has disclosed solutions for reducing rigidity of hydraulically damping elastomer bearings for defined amplitudes. However, these solutions do not permit a quasi-static exchange of fluid between liquid chambers, and, therefore, also do not ensure reduction of the rigidity, independently of an initial load. There is therefore a desire to be able to achieve a reduction in rigidity for defined amplitudes, in particular small amplitudes, wherein a decoupling of an amplitude in a certain force range is to be preferably independent of an initial load.
DE 199 59 391 A1 discloses a hydraulically damping bearing with two chambers that are filled with a hydraulic liquid, and connected to one another via at least one overflow duct and at least one decoupling duct, wherein a movable, oscillatory body that is displaceable along the decoupling duct is accommodated in the decoupling duct, and wherein a device for applying a variable force to the oscillatory body is provided in order to change rigidity properties of the bearing. The oscillatory body is embodied as a hollow cylinder with a dividing wall in which a borehole is provided.
The device for applying the variable force to the oscillatory body of the abovementioned bearing comprises e.g. at least one coil for generating a magnetic field that acts on the oscillatory body, which is fabricated from a magnetic material, so that, by varying the exciter current of the coil, a force applied to the oscillatory body can be varied continuously. Implementing the bearing therefore involves considerable structural and electronic expenditure, which makes the bearing more expensive. Although particularly fine adjustability of the rigidity is possible with this bearing, this is not always necessary in practice. In addition, an integrated orifice in the oscillatory body reduces miniaturization. However, miniaturization is desired in order, on the one hand, to limit installation space and, on the other, to be able to set a clearance by which an inner part can be moved relative to an outer part with the highest possible accuracy until a progression of the bearing rigidity occurs.